So you are growing in soil, indoors ?

Since that is what I am assuming, I will try to offer advice based on that.

First of all I would highly recommend not using Ironite 7-6-6. "crispy on the tips" sound like a realted issue to your fert regimine. I used to use those types of fertilizers when I started growing and I would often end up with problems.

I think it's kinda late to worry much at this point, being so far into flowering, I would continue the flush and harvo as planned.

Brah, my advice is learn from this and make your next crop better by using organic fertilizers;I recommend worm castings and guanos amended to your soil, and in the form of teas.

For a liquid fert I like EarthJuice;Grow,Bloom, and MicroBlast along with my guano and castings.

I can't really say what the prob is exactly, but it seems nute related to me. Get away from using ferts like Ironworks, and you might not see issues like this anymore.

But all in all, your plants look good from the pic I see. I wouldn't worry much.

Hope this helps.

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